Conventionally, a computed radiography (CR) apparatus is widely used as an apparatus used in radiation image capturing for the purpose of diagnosis of disease. In such CR apparatuses, the energy of the radiation which passes the subject is accumulated in the photostimulable phosphor sheet. After capturing, the energy of the radiation accumulated in the photostimulable phosphor sheet is emitted as photostimulable light from the photostimulable phosphor sheet by scanning the photostimulable phosphor sheet with a laser light. The above is converted by photoelectric conversion with a photomultiplier tube, etc. to obtain image data to be used.
Usually, a cassette storing the photostimulable phosphor sheet inside is used in the CR apparatus. In order to load and use the cassette of the CR apparatus on a bucky apparatus (also called bucky capturing stage, etc., see later described FIG. 3) provided in a facility such as a hospital, etc., in which a conventional screen/film cassette is loaded, the cassette of the CR apparatus is usually designed and manufactured in a size similar to the JIS standard size of such screen/film cassette.
Lately, as a method of obtaining the medical radiation image, a radiation image capturing apparatus is developed in which the irradiated radiation is detected with photodiode, etc., to obtain the digital image data. Usually, the radiation image capturing apparatus includes a sensor panel in which a plurality of radiation detecting elements such as a photodiode which generates charge according to the dose of the irradiated radiation are arranged two dimensionally. Since the radiation is detected by a flat plate shaped sensor panel, the apparatus is also known as a flat panel detector (FPD).
Moreover, a cassette type radiation image capturing apparatus (in other words, a portable type radiation image capturing apparatus) in which the sensor panel is stored in a case and can be transported is also used in practice. Similar to the cassette for the CR apparatus, the portable type radiation image capturing apparatus is usually formed in a size conforming to the JIS standard size for the conventional screen/film cassette so that the portable type radiation image capturing apparatus can be loaded and used in an existing bucky apparatus without changing the bucky apparatus existing in a hospital, etc. to a new bucky apparatus (see, for example, Patent Literature 1).
Moreover, such portable radiation image capturing apparatus usually has a configuration so that the apparatus can be used without being loaded on the bucky apparatus. For example, the apparatus is usually configured so that the apparatus can be brought into the hospital room or home of the patient so as to be able to perform radiation image capturing in a state in which the apparatus is directly held against the body of the patient.